Leachates have gradually taken the center stage of environmental discuss in recent times because of their interference with the environment. The potency of any leachate is largely dependent on its concentration which varies with time depending on waste generation patterns, waste stabilization and environmental factors. Leachate pollution index (LPI) provides an overall pollution potential of a landfill site. In this study, the concept of LPI is described in brief and used to estimate the temporal variation of leachate pollution within the dump site. Stepwise procedure to calculate the LPI of a landfill is explained using data from the Yenagoa Central Waste Dump (YCWD) Abanigi Road, Etelebu, Nigeria. This waste dump have no liners or leachate collection/treatment system, therefore, leachate generated finds its way into the environment. LPI values are a comparative scale used as a hazard identification tool. It is an increasing scale index, where a higher value indicates poor environmental condition based on the Delphi technique. Four samples of leachate were taken at different locations within the dumpsite and mixed for homogeneity. The sampling was done twice, ie, during March and December of 2019. The laboratory data was analyzed for its pollution potential using LPI and comparison made between the two sampling regimes. In the present study, leachate samples were collected and analyzed for 9 significant parameters viz pH, TDS, NO3, BOD5, COD, Cu, Zn, Fe and TC. The results obtained showed that the leachate contents were highly contaminated. The March and December analysis showed LPI values of 17.004 and 15.757 respectively, which were beyond the Indian leachate disposal standards for inland surface water (7.378). It was also observed that the leachate concentration during the March analytical period was more toxic than that of the December analytical regime. Therefore, a robust waste management strategy is recommended for the Bayelsa State sanitation Authority.

Recently, surface water pollution has generated grave concerns because of anthropogenic activities including inadequate management of waste. Therefore, this study is concerned with the evaluation of surface water contamination by leachate from uncontrolled landfill in Yenagoa Bayelsa State, Nigeria. Three surface water samples were taken from a stream adjacent to an uncontrolled landfill and analyzed. The Downstream point (SW 1) and Upstream points (SW 3) were taken 50 meters from the southernmost and northernmost ends of the landfill, while the Central point (SW 2) was also taken 50 meters from the central edge of the landfill. The parameters analyzed were, pH, EC, TDS, COD, BOD, TH,NH4+, SO42-, NO3-, Phosphate, Cd, Cr, Cu2+, Pb, Zn, Ca2+, Mg2+, Na+, Fe2+, K+, as well as Total coliform count using standard methods. The concentration of these parameters were compared with NSDWQ and WHO to ascertain their levels within the surface water. The surface water analysis across the Downstream point (SW 1) showed that parameters like pH, EC, TDS, TA, TH, Na, K, Fe, BOD, COD, Phosphate and Total Coliform Count, recorded 7.18, 2,450 μS/cm, 1,225 mg/l, 534.9 mg/l, 270 mg/l, 122.92 mg/l, 69.42 mg/l, 9.48 mg/l, 25 mg/l, 16 mg/l, 7.5 mg/l and 2.80 X 106 cfu/ml respectively. All these values except pH were above NSDWQ and WHO recommended values for potable water. When compared to samples from SW 2 and SW 3, SW 1 samples had higher concentration of parameters. However, some metals and heavy metals like Pb, Cu, Zn, Cd and Cr were below equipment detectable limits for all sampled locations. It was confirmed therefore that the Downstream point (SW 1), was the most contaminated among the three sampled surface water points, in this study. Pearson’s correlational analysis also confirmed that some parameters indicated unity. It was recommended that surface water sources around landfills should be properly monitored to curb water pollution.